diff --git a/lib/Conf.php b/lib/Conf.php
index bd6a620..ff176b0 100644
--- a/lib/Conf.php
+++ b/lib/Conf.php
@@ -21,28 +21,6 @@ class Conf {
     public $dbSQLite3Key            = "";
     /** @var integer Number of seconds for SQLite to wait before returning a timeout error when writing to the database */
     public $dbSQLite3Timeout        = 5;
-    /** @var string Address of host name for PostgreSQL database server (if using PostgreSQL) */
-    public $dbPostgreSQLHost        = "localhost";
-    /** @var string Log-in user name for PostgreSQL database server (if using PostgreSQL) */
-    public $dbPostgreSQLUser        = "arsse";
-    /** @var string Log-in password for PostgreSQL database server (if using PostgreSQL) */
-    public $dbPostgreSQLPass        = "";
-    /** @var integer Listening port for PostgreSQL database server (if using PostgreSQL) */
-    public $dbPostgreSQLPort        = 5432;
-    /** @var string Database name on PostgreSQL database server (if using PostgreSQL) */
-    public $dbPostgreSQLDb          = "arsse";
-    /** @var string Schema name on PostgreSQL database server (if using PostgreSQL) */
-    public $dbPostgreSQLSchema      = "";
-    /** @var string Address of host name for MySQL/MariaDB database server (if using MySQL or MariaDB) */
-    public $dbMySQLHost             = "localhost";
-    /** @var string Log-in user name for MySQL/MariaDB database server (if using MySQL or MariaDB) */
-    public $dbMySQLUser             = "arsse";
-    /** @var string Log-in password for MySQL/MariaDB database server (if using MySQL or MariaDB) */
-    public $dbMySQLPass             = "";
-    /** @var integer Listening port for MySQL/MariaDB database server (if using MySQL or MariaDB) */
-    public $dbMySQLPort             = 3306;
-    /** @var string Database name on MySQL/MariaDB database server (if using MySQL or MariaDB) */
-    public $dbMySQLDb               = "arsse";
 
     /** @var string Class of the user management driver in use (Internal by default) */
     public $userDriver              = User\Internal\Driver::class;
@@ -74,15 +52,15 @@ class Conf {
     /** @var string|null User-Agent string to use when fetching feeds from foreign servers */
     public $fetchUserAgentString;
 
-    /** @var string Amount of time to keep a feed's articles in the database after all its subscriptions have been deleted, as an ISO 8601 duration (default: 24 hours; empty string for forever)
+    /** @var string When to delete a feed from the database after all its subscriptions have been deleted, as an ISO 8601 duration (default: 24 hours; empty string for never)
      * @see https://en.wikipedia.org/wiki/ISO_8601#Durations */
-    public $retainFeeds             = "PT24H";
-    /** @var string Amount of time to keep an unstarred article in the database after it has been marked read by all users, as an ISO 8601 duration (default: 7 days; empty string for forever)
+    public $purgeFeeds             = "PT24H";
+    /** @var string When to delete an unstarred article in the database after it has been marked read by all users, as an ISO 8601 duration (default: 7 days; empty string for never)
      * @see https://en.wikipedia.org/wiki/ISO_8601#Durations */
-     public $retainArticlesRead     = "P7D";
-    /** @var string Amount of time to keep an unstarred article in the database regardless of its read state, as an ISO 8601 duration (default: 21 days; empty string for forever)
+     public $purgeArticlesRead     = "P7D";
+    /** @var string When to delete an unstarred article in the database regardless of its read state, as an ISO 8601 duration (default: 21 days; empty string for never)
      * @see https://en.wikipedia.org/wiki/ISO_8601#Durations */
-     public $retainArticlesUnread     = "P21D";
+     public $purgeArticlesUnread     = "P21D";
 
     /** Creates a new configuration object
      * @param string $import_file Optional file to read configuration data from
diff --git a/lib/Database.php b/lib/Database.php
index 71782e8..a3223c3 100644
--- a/lib/Database.php
+++ b/lib/Database.php
@@ -633,9 +633,9 @@ class Database {
         $this->db->query("UPDATE arsse_feeds set orphaned = CURRENT_TIMESTAMP where orphaned is null and not exists(SELECT id from arsse_subscriptions where feed is arsse_feeds.id)");
         // finally delete feeds that have been orphaned longer than the retention period
         $limit = Date::normalize("now");
-        if(Arsse::$conf->retainFeeds) {
+        if(Arsse::$conf->purgeFeeds) {
             // if there is a retention period specified, compute it; otherwise feed are deleted immediatelty
-            $limit->sub(new \DateInterval(Arsse::$conf->retainFeeds));
+            $limit->sub(new \DateInterval(Arsse::$conf->purgeFeeds));
         }
         $out = (bool) $this->db->prepare("DELETE from arsse_feeds where orphaned <= ?", "datetime")->run($limit);
         // commit changes and return
@@ -913,11 +913,11 @@ class Database {
         );
         $limitRead = null;
         $limitUnread = null;
-        if(Arsse::$conf->retainArticlesRead) {
-            $limitRead = Date::sub(Arsse::$conf->retainArticlesRead);
+        if(Arsse::$conf->purgeArticlesRead) {
+            $limitRead = Date::sub(Arsse::$conf->purgeArticlesRead);
         }
-        if(Arsse::$conf->retainArticlesUnread) {
-            $limitUnread = Date::sub(Arsse::$conf->retainArticlesUnread);
+        if(Arsse::$conf->purgeArticlesUnread) {
+            $limitUnread = Date::sub(Arsse::$conf->purgeArticlesUnread);
         }
         $feeds = $this->db->query("SELECT id, size from arsse_feeds")->getAll();
         foreach($feeds as $feed) {
diff --git a/tests/lib/Database/SeriesCleanup.php b/tests/lib/Database/SeriesCleanup.php
index 9db8b3e..1c6adf7 100644
--- a/tests/lib/Database/SeriesCleanup.php
+++ b/tests/lib/Database/SeriesCleanup.php
@@ -133,7 +133,7 @@ trait SeriesCleanup {
     }
     
     function testCleanUpOldArticlesWithUnlimitedReadRetention() {
-        Arsse::$conf->retainArticlesRead = "";
+        Arsse::$conf->purgeArticlesRead = "";
         Arsse::$db->articleCleanup();
         $state = $this->primeExpectations($this->data, [
             'arsse_articles' => ["id"]
@@ -145,7 +145,7 @@ trait SeriesCleanup {
     }
     
     function testCleanUpOldArticlesWithUnlimitedUnreadRetention() {
-        Arsse::$conf->retainArticlesUnread = "";
+        Arsse::$conf->purgeArticlesUnread = "";
         Arsse::$db->articleCleanup();
         $state = $this->primeExpectations($this->data, [
             'arsse_articles' => ["id"]
@@ -157,8 +157,8 @@ trait SeriesCleanup {
     }
 
     function testCleanUpOldArticlesWithUnlimitedRetention() {
-        Arsse::$conf->retainArticlesRead = "";
-        Arsse::$conf->retainArticlesUnread = "";
+        Arsse::$conf->purgeArticlesRead = "";
+        Arsse::$conf->purgeArticlesUnread = "";
         Arsse::$db->articleCleanup();
         $state = $this->primeExpectations($this->data, [
             'arsse_articles' => ["id"]